Developmental process are activated and shaped by stimulation. Sources of stimulation or experience can be found within the developing organism's habitat. The transition from fetus to newborn infant, heralded by labor and birth, is characterized by a multitude of neural, physiological and behavioral changes that assist successful acclimation to the extrauterine world. The proposed studies focus on intrauterine determinants of neural and behavioral development in relation to labor contractions, the catecholamine system, adult phenotypes and their causal relations. The Norway rat will be used in psychobiological investigations spanning behavioral, physiological, neural and molecular levels of analysis. Intrauterine chemosensory experience, labor contractions, and suckling onset at birth will be analyzed in biobehavioral studies of perinatal learning. Specific effects of labor, i.e., somatosensory stimulation and intermittent hypoxia, will be studied and related to birth complications. Birth-related activation of norepinephrine (NE), dopamine (DA), will be analyzed using pharmacological agents. Neural upregulation of c-fos will be used to guide brain localization studies involving key players in catecholamine systems. To identify relations between intrauterine experience and later developmental phases, adult phenotypes and their emergence will be analyzed. Our framework recognizes the mammalian mother as a pathway for inducing, canalizing, and regulating developmental change. Some studies will analyze whether dams respond differently to pups with different intrauterine experiences. This research program has broad and significant implications for numerous biomedical concerns, including premature birth, birth complications, and stress, psychiatric and pathophysiological disorders, including schizophrenia, substance abuse, attention deficit hyperactivity disorder (ADHD), and Tourette's Syndrome (TS). [unreadable] [unreadable] [unreadable]